Paging method, device, and paging system

ABSTRACT

The present invention discloses a paging method, a device, and a paging system, and relates to the field of wireless communications technologies. The method provided in the present invention includes: receiving, by a base station, a paging message of machine-to-machine user equipment; calculating a paging location of the user equipment; determining a coverage level of the user equipment; and sending an air interface paging message to the user equipment according to the coverage level of the user equipment, and sending, in the paging location, paging scheduling information, where the paging scheduling information is used to indicate a location in which the air interface paging message is sent, and the air interface paging message includes the paging message of the user equipment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2015/071463, filed on Jan. 23, 2015, the disclosure of which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to the field of wireless communicationstechnologies, and in particular, to a paging method, a device, and apaging system.

BACKGROUND

Machine-to-machine (M2M for short) communication is a type of datacommunication of one or more machinery devices that do not need tointeract with a person, where a machinery device (such as a sensor, anelectricity meter, a water meter, or an alarm device) used in the M2Mcommunication may be referred to as user equipment. Because in an M2Mcommunications system, a quantity of user equipment is extremely largeand the user equipment is mostly powered by a battery, for the M2Msystem, replacing a battery each time is an extremely heavy workload. Inview of this, relatively low power consumption and a relatively longstandby time of the user equipment are expected by people. To meet thisfeature of the user equipment, in an idle mode of the M2M communicationssystem, a base station periodically sends a paging message to the userequipment, so that the user equipment is woken up only at a specificinterval according to the paging message sent by the base station, tosend and receive data, and is in a dormant state in another time period,that is, a communication interface of the user equipment is shut down,so as to reduce battery power of the user equipment.

FIG. 1 shows a frame format of a paging message scheduling cycle in anexisting M2M communications system. As shown in FIG. 1, one paging cycle(PC for short) includes several paging frames (English: Paging Frame),and each paging frame includes several paging occasions (PO for short).The PF is a radio frame, and the PO is a radio subframe. Pagingscheduling information is sent to user equipment at a PO moment, wherethe paging scheduling information is downlink control information (DCIfor short), which is used to indicate a location in which a pagingmessage is located. After the paging scheduling message is received bythe user equipment at the PO moment, a location of the paging message isparsed, the paging message is obtained, and the user equipment issuccessfully woken up.

However, in an actual application, when a base station sends a pagingmessage to user equipment, only a transmission mechanism of an existingcellular system is used, and a coverage intensity of a location in whichthe user equipment is located is not taken into consideration. In thiscase, if the user equipment is deployed in an area with a poor coveragesuch as a corner or a basement, the paging message cannot be received bythe user equipment.

SUMMARY

Embodiments of the present invention provide a paging method, a device,and a paging system, so as to resolve an existing problem that userequipment fails to receive a paging message when a coverage intensity ofa location in which the user equipment is located is extremely weak.

To achieve the foregoing objective, the following technical solutionsare used in the embodiments of the present invention:

According to a first aspect, an embodiment of the present inventionprovides a paging method, where the method includes:

receiving, by a base station, a paging message of user equipment, wherethe paging message includes a user identity of the user equipment;

calculating a paging location of the user equipment according to theuser identity of the user equipment, and determining a coverage level ofthe user equipment; and

sending an air interface paging message to the user equipment accordingto the coverage level of the user equipment, and sending, in the paginglocation, paging scheduling information, where the paging schedulinginformation is used to indicate a location in which the air interfacepaging message is sent, and the air interface paging message includesthe paging message of the user equipment.

In a first possible implementation manner of the first aspect, withreference to the first aspect, the determining a coverage level of theuser equipment includes:

if the paging message does not carry the coverage level of the userequipment, and the base station does not store a correspondence betweenthe user equipment and the coverage level, determining that the coveragelevel of the user equipment is a worst coverage level.

In a second possible implementation manner of the first aspect, withreference to the first aspect or the first possible implementationmanner of the first aspect, the sending an air interface paging messageto the user equipment according to the coverage level of the userequipment includes:

combining paging messages with a paging location and a coverage levelthat are the same as those of the user equipment into a same pagingrecord list;

making the paging record list included in an air interface pagingmessage that is corresponding to the user equipment; and

using, according to a preset correspondence between a coverage level anda modulation and coding scheme MCS, an MCS that is corresponding to thecoverage level of the user equipment to perform modulation and coding onthe air interface paging message, and sending the modulated and codedair interface paging message to the user equipment.

In a third possible implementation manner of the first aspect, withreference to any one of the first aspect to the second possibleimplementation manner of the first aspect, the receiving, by a basestation, a paging message of user equipment includes:

receiving, by the base station, a paging message of the user equipmentsent by a mobility management entity MME or a serving general packetradio service support node SGSN.

In a fourth possible implementation manner of the first aspect, withreference to the third possible implementation manner of the firstaspect, the calculating a paging location of the user equipmentincludes:

calculating, according to a paging cycle of a network configuration, apaging super frame density, and an equipment identity of the userequipment, a paging super frame in which the paging location is located;and

calculating, according to a quantity of paging occasions within onepaging super frame, the equipment identity of the user equipment, andthe paging super frame density, a paging occasion on which the paginglocation is located, where

the quantity of the paging occasions within the paging super frame isdetermined according to a length of the paging super frame and adownlink control information interval.

In a fifth possible implementation manner of the first aspect, withreference to any one of the first aspect to the fourth possibleimplementation manner of the first aspect, the method further includes:

re-determining a coverage level of the user equipment if the basestation receives retransmission indication information that is used toinstruct to re-send a paging message of the user equipment; and

sending an air interface paging message to the user equipment accordingto the re-determined coverage level of the user equipment.

In a sixth possible implementation manner of the first aspect, withreference to the fifth possible implementation manner of the firstaspect, the re-determining a coverage level of the user equipmentincludes:

if the retransmission indication message received by the base stationincludes a current coverage level of the user equipment, determiningthat the coverage level of the user equipment is the current coveragelevel; or

if the retransmission indication message received by the base stationdoes not include a current coverage level of the user equipment,lowering the coverage level of the user equipment to a next inferiorcoverage level, or determining that the coverage level of the userequipment is the worst coverage level.

According to a second aspect, an embodiment of the present inventionprovides a paging method, including:

receiving, by user equipment and in a paging location, paging schedulinginformation sent by a base station, where the paging scheduling messageis coded according to a modulation and coding scheme MCS that iscorresponding to a coverage level of the user equipment, and is used toindicate a location of an air interface paging message sent by the basestation to the user equipment, where the coverage level of the userequipment is reported to an MME or an SGSN by the user equipment, anddelivered to the base station by the MME or the SGSN; and

decoding, by the user equipment, the paging scheduling informationaccording to an MCS that is corresponding to a current coverage level ofthe user equipment.

In a first possible implementation manner of the second aspect, withreference to the second aspect, the method further includes:

if the user equipment successfully parses the paging schedulinginformation, receiving, according to the location indicated by thepaging scheduling information, the air interface paging message sent bythe base station, and obtaining a paging message of the user equipmentfrom the air interface paging message; or

if the user equipment fails to parse the paging scheduling information,reporting the current coverage level of the user equipment to the MME orthe SGSN by using the base station.

In a second possible implementation manner of the second aspect, withreference to the first possible implementation manner of the secondaspect, the reporting the current coverage level of the user equipmentto the MME or the SGSN by using the base station includes:

reporting, by the user equipment, a random access message that carriesthe current coverage level of the user equipment to the base station,and instructing the base station to report the current coverage level ofthe user equipment to the MME or the SGSN; or

reporting, by the user equipment, a registration Attach message, or atracking area update TAU message, or a routing area update RAU messagethat carries the current coverage of the user equipment to the basestation, and instructing the base station to forward the Attach message,or the TAU message, or the RAU message to the MME or the SGSN.

According to a third aspect, an embodiment of the present inventionprovides a base station, including:

a receiving unit, configured to receive a paging message of userequipment, where the paging message includes a user identity of the userequipment;

a calculating unit, configured to calculate a paging location of theuser equipment according to the user identity received by the receivingunit;

a determining unit, configured to determine a coverage level of the userequipment according to the user identity received by the receiving unit;and

a sending unit, configured to send an air interface paging message tothe user equipment according to the coverage level of the user equipmentdetermined by the determining unit, and send, in the paging locationcalculated by the calculating unit, paging scheduling information, wherethe paging scheduling information is used to indicate a location inwhich the air interface paging message is sent, and the air interfacepaging message includes the paging message of the user equipment.

In a first possible implementation manner of the third aspect, withreference to the third aspect, the determining unit is specificallyconfigured to:

if the paging message does not carry the coverage level of the userequipment, and the base station does not store a correspondence betweenthe user equipment and the coverage level, determine that the coveragelevel of the user equipment is a worst coverage level.

In a second possible implementation manner of the third aspect, withreference to the third aspect or the first possible implementationmanner of the third aspect, the sending unit is specifically configuredto:

combine paging messages with a paging location and a coverage level thatare the same as those of the user equipment into a same paging recordlist;

make the paging record list included in an air interface paging messagethat is corresponding to the user equipment; and

use, according to a preset correspondence between a coverage level and amodulation and coding scheme MCS, an MCS that is corresponding to thecoverage level of the user equipment to perform modulation and coding onthe air interface paging message, and send the modulated and coded airinterface paging message to the user equipment.

In a third possible implementation manner of the third aspect, withreference to any one of the third aspect to the second possibleimplementation manner of the third aspect, the receiving unit isspecifically configured to:

receive a paging message of the user equipment sent by an MME or anSGSN.

In a fourth possible implementation manner of the third aspect, withreference to the third possible implementation manner of the thirdaspect, the calculating unit is specifically configured to:

calculate, according to a paging cycle of a network configuration, apaging super frame density, and an equipment identity of the userequipment, a paging super frame in which the paging location is located;and

calculate, according to a quantity of paging occasions within one pagingsuper frame, the equipment identity of the user equipment, and thepaging super frame density, a paging occasion on which the paginglocation is located, where

the quantity of the paging occasions within the paging super frame isdetermined according to a length of the paging super frame and adownlink control information interval.

In a fifth possible implementation manner of the third aspect, withreference to any one of the third aspect to the fourth possibleimplementation manner of the third aspect, the determining unit isfurther configured to re-determine a coverage level of the userequipment if the receiving unit receives retransmission indicationinformation that is used to instruct to re-send a paging message of theuser equipment; and

the sending unit is further configured to send an air interface pagingmessage to the user equipment according to the coverage level of theuser equipment re-determined by the determining unit.

In a sixth possible implementation manner of the third aspect, withreference to the fifth possible implementation manner of the thirdaspect, the determining unit is specifically configured to:

if the retransmission indication message received by the base stationincludes a current coverage level of the user equipment, determine thatthe coverage level of the user equipment is the current coverage level;or

if the retransmission indication message received by the base stationdoes not include a current coverage level of the user equipment, lowerthe coverage level of the user equipment to a next inferior coveragelevel, or determine that the coverage level of the user equipment is theworst coverage level.

According to a fourth aspect, an embodiment of the present inventionprovides user equipment, including:

a receiving unit, configured to receive, in a paging location, pagingscheduling information sent by a base station, where the pagingscheduling message is coded according to a modulation and coding schemeMCS that is corresponding to a coverage level of the user equipment, andis used to indicate a location of an air interface paging message sentby the base station to the user equipment, where the coverage level ofthe user equipment is reported to an MME or an SGSN by the userequipment, and delivered to the base station by the MME or the SGSN; and

a parsing unit, configured to decode the paging scheduling informationaccording to an MCS that is corresponding to a current coverage level ofthe user equipment.

In a first possible implementation manner of the fourth aspect, withreference to the fourth aspect, if the user equipment successfullyparses the paging scheduling information, the user equipment furtherincludes:

an obtaining unit, configured to: if the parsing unit successfullyparses the paging scheduling information, receive, according to thelocation indicated by the paging scheduling information that is receivedby the receiving unit, the air interface paging message sent by the basestation, and obtain a paging message of the user equipment from the airinterface paging message; and

a reporting unit, configured to: if the parsing unit fails to parse thepaging scheduling information, report the current coverage level of theuser equipment to the base station.

In a second possible implementation manner of the fourth aspect, withreference to the first possible implementation manner of the fourthaspect, the reporting unit is specifically configured to:

report a random access message that carries the current coverage levelof the user equipment to the base station, and instruct the base stationto report the current coverage level of the user equipment to the MME orthe SGSN; or

report a registration Attach message, or a tracking area update TAUmessage, or a routing area update RAU message that carries the currentcoverage of the user equipment to the base station, and instruct thebase station to forward the Attach message, or the TAU message, or theRAU message to the MME or the SGSN.

According to a fifth aspect, an embodiment of the present inventionprovides a paging system, including: the base station according to anyone of the third aspect to the sixth possible implementation manner ofthe third aspect, the user equipment according to any one of the fourthaspect to the second possible implementation manner of the fourthaspect, and a core network device, where

the core network device is an MME or an SGSN.

According to a sixth aspect, an embodiment of the present inventionprovides a base station, including:

a communications unit, configured to receive a paging message ofmachine-to-machine user equipment, where the paging message includes auser identity of the user equipment; and

a processor, configured to calculate a paging location of the userequipment and determine a coverage level of the user equipment,according to the user identity received by the communications unit,where

the communications unit is further configured to send an air interfacepaging message to the user equipment according to the coverage level ofthe user equipment determined by the processor, and send, in the paginglocation calculated by the processor, paging scheduling information,where the paging scheduling information is used to indicate a locationin which the air interface paging message is sent, and the air interfacepaging message includes the paging message of the user equipment.

In a first possible implementation manner of the sixth aspect, withreference to the sixth aspect, the processor is specifically configuredto:

if the paging message does not carry the coverage level of the userequipment, and the base station does not store a correspondence betweenthe user equipment and the coverage level, determine that the coveragelevel of the user equipment is a worst coverage level.

In a second possible implementation manner of the sixth aspect, withreference to the sixth aspect or the first possible implementationmanner of the sixth aspect, the communications unit is specificallyconfigured to:

combine paging messages with a paging location and a coverage level thatare the same as those of the user equipment into a same paging recordlist;

make the paging record list included in an air interface paging messagethat is corresponding to the user equipment; and

use, according to a preset correspondence between a coverage level and amodulation and coding scheme MCS, an MCS that is corresponding to thecoverage level of the user equipment to perform modulation and coding onthe air interface paging message, and send the modulated and coded airinterface paging message to the user equipment.

In a third possible implementation manner of the sixth aspect, withreference to any one of the sixth aspect to the second possibleimplementation manner of the sixth aspect, the communications unit isspecifically configured to:

receive a paging message of the user equipment sent by an MME or anSGSN.

In a fourth possible implementation manner of the sixth aspect, withreference to the third possible implementation manner of the sixthaspect, the processor is specifically configured to:

calculate, according to a paging cycle of a network configuration, apaging super frame density, and an equipment identity of the userequipment, a paging super frame in which the paging location is located;and

calculate, according to a quantity of paging occasions within one pagingsuper frame, the equipment identity of the user equipment, and thepaging super frame density, a paging occasion on which the paginglocation is located, where

the quantity of the paging occasions within the paging super frame isdetermined according to a length of the paging super frame and adownlink control information interval.

In a fifth possible implementation manner of the sixth aspect, withreference to any one of the sixth aspect to the fourth possibleimplementation manner of the sixth aspect,

the processor is further configured to re-determine a coverage level ofthe user equipment if the communications unit receives retransmissionindication information that is used to instruct to re-send a pagingmessage of the user equipment; and

the communications unit is further configured to send an air interfacepaging message to the user equipment according to the coverage level ofthe user equipment re-determined by the processor.

In a sixth possible implementation manner of the sixth aspect, withreference to the fifth possible implementation manner of the sixthaspect, the processor is specifically configured to:

if the retransmission indication message received by the base stationincludes a current coverage level of the user equipment, determine thatthe coverage level of the user equipment is the current coverage level;or

if the retransmission indication message received by the base stationdoes not include a current coverage level of the user equipment, lowerthe coverage level of the user equipment to a next inferior coveragelevel, or determine that the coverage level of the user equipment is theworst coverage level.

According to a seventh aspect, an embodiment of the present inventionprovides user equipment, including:

a communications unit, configured to receive, in a paging location,paging scheduling information sent by a base station, where the pagingscheduling message is coded according to a modulation and coding schemeMCS that is corresponding to a coverage level of the user equipment, andis used to indicate a location of an air interface paging message sentby the base station to the user equipment, where the coverage level ofthe user equipment is reported to an MME or an SGSN by the userequipment, and delivered to the base station by the MME or the SGSN; and

a processor, configured to decode, according to an MCS that iscorresponding to a current coverage level of the user equipment, thepaging scheduling information received by the communications unit.

In a first possible implementation manner of the seventh aspect, withreference to the seventh aspect, the processor is further configured to:if the processor successfully parses the paging scheduling information,receive, according to the location indicated by the paging schedulinginformation, the air interface paging message sent by the base station,and obtain a paging message of the user equipment from the air interfacepaging message; and

the communications unit is further configured to: if the processor failsto parse the paging scheduling information, report the current coveragelevel of the user equipment to the base station.

In a second possible implementation manner of the seventh aspect, withreference to the first possible implementation manner of the seventhaspect, the communications unit is specifically configured to:

report a random access message that carries the current coverage levelof the user equipment to the base station, and instruct the base stationto report the random access message to the MME or the SGSN, so that theMME or the SGSN sends, to the base station, retransmission indicationinformation that is used to instruct to re-send a paging message of theuser equipment.

According to an eighth aspect, an embodiment of the present inventionprovides a paging system, including: the base station according to anyone of the sixth aspect to the sixth possible implementation manner ofthe sixth aspect, the user equipment according to any one of the seventhaspect to the second possible implementation manner of the seventhaspect, and a core network device, where

the core network device is an MME or an SGSN.

It may be learned from the foregoing that the embodiments of the presentinvention provide a paging method, a device, and a paging system. Whenreceiving a paging message of user equipment, a base station calculatesa paging location of the user equipment and obtains a coverage level ofthe user equipment; and the base station sends an air interface pagingmessage to the user equipment according to the coverage level of theuser equipment, and sends, in the paging location, paging schedulinginformation, where the paging scheduling information is used to indicatea location in which the air interface paging message is sent, and theair interface paging message includes the paging message of the userequipment. Therefore, compared with the prior art, it is implementedthat in an M2M communications system, a base station sends a pagingmessage to user equipment according to a coverage level of the userequipment, so that user equipment in different coverage areas canproperly receive a paging message to some extent, and a quantity oftimes of re-sending a paging message is reduced, thereby avoiding anexisting problem that the user equipment fails to receive the pagingmessage when a coverage intensity of a location in which the userequipment is located is extremely weak, where the problem is caused dueto a fact that the base station sends the paging message to the userequipment without considering the coverage intensity of the location inwhich the user equipment is located.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention or in the prior art more clearly, the following brieflydescribes the accompanying drawings required for describing theembodiments or the prior art. Apparently, the accompanying drawings inthe following description show merely some embodiments of the presentinvention, and a person of ordinary skill in the art may still deriveother drawings from these accompanying drawings without creativeefforts.

FIG. 1 is a frame format of a paging message scheduling cycle in anexisting M2M communications system;

FIG. 2 is an application scenario of a paging method according to anembodiment of the present invention;

FIG. 3 is a flowchart of a paging method according to another embodimentof the present invention;

FIG. 4 is a frame format of a paging message scheduling cycle accordingto an embodiment of the present invention;

FIG. 5 is a flowchart of a paging method according to still anotherembodiment of the present invention;

FIG. 6A and FIG. 6B are a flowchart of a paging method according toanother embodiment of the present invention;

FIG. 7 is a structural diagram of a base station according to anembodiment of the present invention;

FIG. 8 is a structural diagram of user equipment according to anembodiment of the present invention;

FIG. 8A is a structural diagram of user equipment according to anembodiment of the present invention;

FIG. 8B is a structural diagram of user equipment according to anembodiment of the present invention;

FIG. 9 is a structural diagram of a paging system according to anembodiment of the present invention;

FIG. 10 is a structural diagram of a base station according to anotherembodiment of the present invention;

FIG. 11 is a structural diagram of user equipment according to anotherembodiment of the present invention; and

FIG. 12 is a structural diagram of a paging system according to anotherembodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are merely some but not all of the embodiments ofthe present invention. All other embodiments obtained by a person ofordinary skill in the art based on the embodiments of the presentinvention without creative efforts shall fall within the protectionscope of the present invention.

A paging method provided in embodiments of the present invention notonly applies to a Long Term Evolution (LTE for short) network system,but also applies to any one of the following network systems: a LongTerm Evolution-Advanced (LTE-A for short) system, the Universal MobileTelecommunications System (UMTS for short), the Global System for MobileCommunication (GSM for short), and the like. However, the embodiments ofthe present invention impose no limitation on a specific communicationssystem to which the paging method applies, and in the embodiments of thepresent invention, only a case in which the paging method applies to theLTE system is used as an example for description. FIG. 2 shows anapplication scenario of a paging method according to an embodiment ofthe present invention, where the scenario may include: multiple userequipments, a base station, a core network device. The user equipmentmay also be referred to as machine type communication (MTC for short),which may be any type of device without human interaction, and performan information exchange by using the base station. The user equipmentmay be located in a location with a relatively high coverage level, forexample, a strong coverage area in an existing cellular network, or maybe located in a location with an extremely low coverage level, forexample, a weak coverage area (a corner, a basement, or the like) in anexisting cellular network. The core network device may be a mobilitymanagement entity (English: Mobility Management Entity, MME for short)that is connected to the base station by using an S1 interface, or maybe a serving GPRS (English: General Packet Radio Service) support node(SGSN for short) that is connected to the base station by using a Gbinterface. For user equipment at a strong coverage level, a transmissiongain of a paging message does not need to be increased, and the userequipment may properly receive the paging message. However, for userequipment at an extremely low coverage level, corresponding processingof increasing a transmission gain (such as increasing a transmission bitrate, changing a coding scheme, or spreading a spectrum) needs to beperformed on a paging message, so that the user equipment can properlyreceive the paging message; that is, the paging message sent to the userequipment needs to be processed in different manners according to acoverage level of the user equipment, so that the user equipment canproperly receive the paging message. In view of this, in the embodimentsof the present invention, when the core network device needs to pageuser equipment, after a paging message is sent to the base station, thebase station processes the paging message at a specific moment accordingto a current coverage level of the user equipment, and sends theprocessed paging message to the user equipment, so that the userequipment can properly receive the paging message. The followingdescribes the paging method provided in the embodiments of the presentinvention.

Embodiment 1

FIG. 3 shows a flowchart of a paging method according to Embodiment 1 ofthe present invention. As shown in FIG. 3, the method may include:

301. A base station receives a paging message of user equipment.

Preferably, the base station may receive, by using S1, a paging messageof the user equipment sent by an MME; or receive, by using a Gbinterface, a paging message of the user equipment sent by an SGSN.

The paging message includes a user identity of the user equipment, andis used to wake up user equipment that is in an idle state.

302. The base station calculates a paging location of the user equipmentaccording to a user identity of the user equipment.

The paging location is used to send paging scheduling information, wherethe paging scheduling information is used to indicate a sending locationin which the base station sends an air interface paging message to theuser equipment. It should be noted that in this embodiment of thepresent invention, a frame format of a paging message scheduling cycleis different from that shown in FIG. 1. As shown in FIG. 4, in thisembodiment of the present invention, each paging cycle includes severalpaging super frames (Paging Super Frame), and each paging super frameincludes several paging occasions (Paging Occasion). The paging occasionis a radio frame and is equivalent to a paging frame shown in FIG. 1,and the paging occasion is a paging location and is used to beardownlink control information (Downlink Control Information, DCI), forexample, paging scheduling information. Each piece of downlink controlinformation occupies one radio frame and is equivalent to occupying onepaging occasion shown in FIG. 1.

Preferably, the base station may calculate, according to a paging cycleof a network configuration, a paging super frame density, and anequipment identity of the user equipment, a paging super frame in whichthe paging location is located; for example, determine, according to aformula: SFN mod T=(T div N)*(UE_ID mod N), the paging super frame inwhich the paging message is located; and

calculate, according to a quantity of paging occasions within one pagingsuper frame, the equipment identity of the user equipment, and thepaging super frame density, a paging occasion on which the paginglocation is located; for example, determine, according to a formula:PO=floor(UE_ID/N) mod Ns, the paging occasion on which the pagingmessage is located.

Symbols in the foregoing formulas: “mod” indicates dividing two integersto take a remainder; “div” indicates dividing two integers; “*”indicates multiplying two integers; “floor” indicates rounding down; and“/” indicates dividing two numbers.

Parameters in the foregoing formulas: UE_ID indicates the equipmentidentity of the user equipment that is used to identify the userequipment, and may be any one of the following identities: aninternational mobile subscriber identity (IMSI for short), a temporarymobile subscriber identity (TMSI for short), a globally unique temporaryUE identity Globally Unique Temporary UE Identity, and an internationalmobile equipment identity (IMEI for short).

T indicates the paging cycle.

Ns indicates a quantity of paging occasions (PO) in one downlink controlinformation interval (DCI interval), and a value is: Ns=ceil (the lengthof a super frame/the length of DCI interval), that is, the quantity ofthe paging occasions is equal to an integer value that is obtained byrounding up a quotient of a length of the paging super frame divided bythe downlink control information interval. For example, in a current M2Mcommunications system, the length of the super frame is 64 radio frames(radio frame). In this case, if the DCI interval is 64 radio frames, Nsis 1 at most; if the DCI interval is 32 radio frames, Ns is 2 at most;or if the DCI interval is one radio frame, Ns is 64 at most.

N indicates the paging super frame density in a paging cycle. Forexample, N=T/4 indicates that in one paging cycle T, every four superframes may have only one paging super frame; N=T/2 indicates that in onepaging cycle T, every two super frames have only one paging super frame;and N=T indicates that in one paging cycle T, every super frame may be apaging super frame.

303. The base station determines a coverage level of the user equipment.

The coverage level is used to indicate a network coverage intensity of alocation in which the user equipment is located, which may be dividedinto different levels according to a system regulation. Generally, threecoverage levels are designed in a narrowband system, and arerespectively: a level 0, a level 1, and a level 2. A higher coveragelevel indicates a lower network coverage intensity, and it is morenecessary to use a modulation and coding scheme that can increase thenetwork coverage intensity. The coverage level may be included in thepaging message, or pre-stored in the base station.

In addition, if the coverage level is not included in the pagingmessage, or is not pre-stored in the base station, the base stationdetermines that the coverage level of the user equipment is a worstcoverage level.

304. The base station sends an air interface paging message to the userequipment according to the coverage level of the user equipment, andsends, in the paging location, paging scheduling information, where thepaging scheduling information is used to indicate a location in whichthe air interface paging message is sent, and the air interface pagingmessage includes the paging message of the user equipment.

The air interface paging message is one or more M2M paging messages thatare sent over a same air interface.

Preferably, the base station may combine paging messages with a paginglocation and a coverage level that are the same as those of the userequipment into a same paging record list;

make the paging record list included in an air interface paging messagethat is corresponding to the user equipment; and

use, according to a preset correspondence between a coverage level and amodulation and coding scheme MCS, an MCS that is corresponding to thecoverage level of the user equipment to perform modulation and coding onthe air interface paging message, and send the modulated and coded airinterface paging message to the user equipment.

The paging record list includes: a paging message and a correspondencebetween the paging message and the user equipment.

The correspondence between a coverage level and a modulation and codingscheme MCS is set in an M2M communication process according to arequirement, which is not limited in this embodiment of the presentinvention.

For example, if a paging super frame in a paging location of userequipment 1 is the first super frame, a paging occasion is the sixthradio frame, and a coverage level of the user equipment 1 is the level1, if a paging super frame in a paging location of user equipment 2 isthe first super frame, a paging occasion is the sixth radio frame, and acoverage level of the user equipment 2 is the level 1, and if a pagingsuper frame in a paging location of user equipment 3 is the first superframe, a paging occasion is the sixth radio frame, and a coverage levelof the user equipment 3 is the level 1, paging messages of the userequipment 1, the user equipment 2, and the user equipment 3 may becombined into a same paging record list, and the paging record list istransmitted by using an air interface.

TABLE 1 Paging message Equipment identity Paging message 1 Userequipment 1 Paging message 2 User equipment 2 Paging message 3 Userequipment 3

Obviously, in step 304, the base station may use a default modulationand coding scheme (for example, a modulation and coding scheme that iscorresponding to the worst coverage level) to send the paging message;may use, according to a coverage level of the user equipment sent by theMME or the SGSN, a corresponding modulation and coding scheme totransmit the paging message; or may use, according to a coverage levelof the user equipment stored in the inside of the base station, acorresponding modulation and coding scheme to transmit a paging messageset. Therefore, it is implemented that a paging message is sent to userequipment according to a coverage level of the user equipment, so thatuser equipment at different coverage levels obtains, to some extent, apaging message that is corresponding to the user equipment, and returnsa response message indicating that the paging is successful to the MMEand the SGSN. However, because the user equipment may be moved to someextent, and a communication environment in which the user equipment islocated is changing, a coverage level of the user equipment determinedby the base station this time cannot accurately represent a currentcoverage level of the user equipment; if a paging message is sent afterbeing modulated and coded according to an MCS that is corresponding tothe coverage level, the user equipment cannot obtain the paging messagebecause the user equipment fails to parse paging scheduling information,which further brings about paging message re-sending. Therefore, toreduce a quantity of times of re-sending a paging message of the userequipment, the method further includes:

re-determining a coverage level of the user equipment if the basestation receives retransmission indication information that is used toinstruct to re-send a paging message of the user equipment; and

sending an air interface paging message to the user equipment accordingto the re-determined coverage level of the user equipment.

Exemplarily, the re-determining a coverage level of the user equipmentmay include:

if the retransmission indication message received by the base stationincludes a current coverage level of the user equipment, determiningthat the coverage level of the user equipment is the current coveragelevel; or

if the retransmission indication message received by the base stationdoes not include a current coverage level of the user equipment,lowering the coverage level of the user equipment to a next inferiorcoverage level, or determining that the coverage level of the userequipment is the worst coverage level.

It may be learned from the foregoing that this embodiment of the presentinvention provides a paging method. When receiving a paging message ofuser equipment, a base station calculates a paging location of the userequipment and determines a coverage level of the user equipment; and thebase station sends an air interface paging message to the user equipmentaccording to the coverage level of the user equipment, and sends, in thepaging location, paging scheduling information, where the pagingscheduling information is used to indicate a location in which the airinterface paging message is sent, and the air interface paging messageincludes the paging message of the user equipment. Therefore, it isimplemented that in an M2M communications system, a base station sends apaging message to user equipment according to a coverage level of theuser equipment, so that user equipment in different coverage areas canproperly receive a paging message to some extent, and a quantity oftimes of re-sending a paging message is reduced, thereby avoiding anexisting problem that the user equipment fails to receive the pagingmessage when a coverage intensity of a location in which the userequipment is located is extremely weak, where the problem is caused dueto a fact that the base station sends the paging message to the userequipment without considering the coverage intensity of the location inwhich the user equipment is located.

Embodiment 2

FIG. 5 shows a flowchart of a paging method according to Embodiment 2 ofthe present invention. As shown in FIG. 5, the method may include:

501. User equipment receives, in a paging location, paging schedulinginformation sent by a base station.

The paging scheduling message is coded according to a modulation andcoding scheme MCS that is corresponding to a coverage level of the userequipment, and is used to indicate a location of an air interface pagingmessage sent by the base station to the user equipment, where thecoverage level of the user equipment is reported to an MME or an SGSN bythe user equipment, and delivered to the base station by the MME or theSGSN.

The air interface paging message includes a paging message record list,where the paging message record list includes a paging message of atleast one user equipment and a correspondence between the paging messageof the user equipment and the user equipment. In the paging messagelist, a paging location of a paging message and a coverage level thatare of each user equipment are the same as the paging location and thecoverage level that are of the user equipment.

It should be noted that a method for calculating a paging location bythe user equipment is the same as a method for calculating a paginglocation by the base station, and details are not described herein.

502. The user equipment decodes the paging scheduling informationaccording to an MCS that is corresponding to a current coverage level ofthe user equipment.

The user equipment may determine the current coverage level of the userequipment according to a reference signal received power (RSRP forshort).

Further, if the user equipment successfully parses the paging schedulinginformation, it indicates that a coverage level used when the basestation sends the paging scheduling information is the same as or lowerthan the current coverage level of the user equipment, and the methodfurther includes:

receiving, by the user equipment according to the location indicated bythe paging scheduling information, the air interface paging message sentby the base station, and obtaining a paging message of the userequipment from the air interface paging message.

If the user equipment fails to parse the paging scheduling information,it indicates that a coverage level used when the base station sends thepaging scheduling information is higher than the current coverage levelof the user equipment, and the user equipment needs to report thecurrent coverage level of the user equipment to the MME or the SGSN.

Exemplarily, that the user equipment reports the current coverage levelof the user equipment to the MME or the SGSN may include:

reporting, by the user equipment, a random access message that carriesthe current coverage level of the user equipment to the base station,and instructing the base station to report the current coverage level ofthe user equipment to the MME or the SGSN; or

reporting, by the user equipment, a registration Attach message, or atracking area update (Tracking Area Update, TAU) message, or a routingarea update (Route Area Update, RAU) message that carries the currentcoverage of the user equipment to the base station, and instructing thebase station to forward the Attach message, or the TAU message, or theRAU message to the MME or the SGSN.

It may be learned from the foregoing that this embodiment of the presentinvention provides a paging method. After user equipment receives pagingscheduling information sent by a base station, if the user equipmentsuccessfully parses the paging scheduling information, the userequipment receives, according to a location indicated by the pagingscheduling information, an air interface paging message sent by the basestation, and obtains a paging message of the user equipment from the airinterface paging message; or if the user equipment fails to parse thepaging scheduling information, the user equipment reports a currentcoverage level of the user equipment to the base station, so that whenre-sending a paging message to the user equipment, the base stationre-sends the message to the user equipment according to the currentcoverage level of the user equipment. Therefore, it is implemented thatin an M2M communications system, a base station sends a paging messageto user equipment according to a coverage level of the user equipment,so that user equipment in different coverage areas can properly receivea paging message to some extent, and a quantity of times of re-sending apaging message is reduced, thereby avoiding an existing problem that theuser equipment fails to receive the paging message when a coverageintensity of a location in which the user equipment is located isextremely weak, where the problem is caused due to a fact that the basestation sends the paging message to the user equipment withoutconsidering the coverage intensity of the location in which the userequipment is located.

The following uses the application scenario shown in FIG. 2 as anexample to describe a paging method provided in the present invention indetail by using Embodiment 3.

Embodiment 3

FIG. 6A and FIG. 6B are a flowchart of a paging method according to thisembodiment of the present invention. As shown in FIG. 6A and FIG. 6B,the method may include:

601. A core network device sends a paging message of user equipment to abase station.

Preferably, the core network device sends the paging message of the userequipment to the base station by using an S1 interface or a Gbinterface.

The paging message is used to wake up user equipment that is in an idlestate.

602. The base station calculates a paging location of the userequipment.

The paging location is determined by a paging super frame and a pagingoccasion, and is used to send paging scheduling information, where thepaging scheduling information is used to indicate a sending location inwhich the base station sends an air interface paging message to the userequipment.

Preferably, the base station may calculate the paging super frameaccording to a paging cycle of a network configuration, a paging superframe density, and an equipment identity of the user equipment; forexample, determine, according to a formula: SFN mod T=(T div N)*(UE_IDmod N), the paging super frame in which the paging location is located;and

calculate the paging occasion according to a quantity of pagingoccasions within one paging super frame, the equipment identity of theuser equipment, and the paging super frame density; for example,determine, according to a formula: PO=floor(UE_ID/N) mod Ns, the pagingoccasion on which the paging location is located.

603. The base station determines a coverage level of the user equipment.

The coverage level is used to indicate a network coverage intensity of alocation in which the user equipment is located, which may be dividedinto different levels according to a system regulation. Generally, threecoverage levels are designed in a narrowband system, and arerespectively: a level 0, a level 1, and a level 2. A higher coveragelevel indicates a lower network coverage intensity, and it is morenecessary to use a modulation and coding scheme that can increase thenetwork coverage intensity. The coverage level may be included in thepaging message, or pre-stored in the base station.

In addition, if the coverage level is not included in the pagingmessage, or is not pre-stored in the base station, the base stationdetermines that the coverage level of the user equipment is a worstcoverage level.

604. The base station sends an air interface paging message to the userequipment according to the coverage level of the user equipment, andsends, in the paging location, paging scheduling information.

The paging scheduling information is used to indicate a location inwhich the air interface paging message is sent, and the air interfacepaging message includes the paging message of the user equipment, wherethe air interface paging message is one or more paging messages of theuser equipment that are sent over a same air interface.

Preferably, the base station may combine paging messages with a paginglocation and a coverage level that are the same as those of the userequipment into a same paging record list;

make the paging record list included in an air interface paging messagethat is corresponding to the user equipment; and

use, according to a preset correspondence between a coverage level and amodulation and coding scheme MCS, an MCS that is corresponding to thecoverage level of the user equipment to perform modulation and coding onthe air interface paging message, and send the modulated and coded airinterface paging message to the user equipment.

The paging record list includes: a paging message and a correspondencebetween the paging message and the user equipment.

605. The user equipment receives, in the paging location, the pagingscheduling information sent by the base station.

It should be noted that a method for calculating a paging location bythe user equipment is the same as a method for calculating a paginglocation by the base station.

606. The user equipment parses the paging scheduling message, and if theuser equipment successfully parses the paging scheduling information,steps 607 and 608 are performed; or if the user equipment fails to parsethe paging scheduling information, steps 609 and 610 are performed.

Preferably, the user equipment may parse the paging scheduling messageby using a modulation and coding scheme that is corresponding to acoverage level determined by the user equipment. The user equipment maydetermine the coverage level of the user equipment according to areference signal received power (English: Reference Signal ReceivingPower, RSRP for short).

607. The user equipment receives, according to a location indicated bythe paging scheduling information, the air interface paging message sentby the base station, and obtains the paging message of the userequipment from the air interface paging message.

608. The user equipment returns a response message used to indicate thatthe paging is successful to the core network device by using the basestation.

609. The user equipment reports a random access message that carries acurrent coverage level of the user equipment to the base station.

610. The base station reports the random access message that carries thecurrent coverage level of the user equipment to the core network deviceby using a first S1 or Gb interface.

611. When receiving no response message within a preset time, the corenetwork device sends retransmission indication information to the basestation by using a second S1 or Gb interface, where the retransmissionindication information is indication information that is used toinstruct to re-send a paging message of the user equipment; if theretransmission indication message includes the current coverage level ofthe user equipment, step 612 is performed; or if the retransmissionindication message does not include the current coverage level of theuser equipment, step 613 is performed.

612. The base station re-sends a paging message to the user equipmentaccording to the coverage level of the user equipment obtained by usingthe second S1 or Gb interface.

613. The base station re-determines that the coverage level of the userequipment is a next inferior coverage level or a worst coverage level.

614. The base station sends a paging message to the user equipmentaccording to the re-determined coverage level of the user equipment.

It may be learned from the foregoing that this embodiment of the presentinvention provides a paging method. After receiving a paging message ofuser equipment sent by a core network device, a base station calculatesa paging location of the user equipment, sends an air interface pagingmessage to the user equipment according to a determined coverage levelof the user equipment, and sends, in the paging location, pagingscheduling information; after receiving the paging schedulinginformation sent by the base station, the user equipment parses thepaging scheduling message and obtains the paging message; if the parsingsucceeds, the user equipment returns a response message; or if theparsing fails, the user equipment reports a current coverage level ofthe user equipment, so that the base station re-sends a paging messageto the user equipment according to the current coverage level, or theuser equipment does not report a current coverage level, so that thebase station re-sends a paging message to the user equipment accordingto a re-determined coverage level. Therefore, it is implemented that inan M2M communications system, a base station sends a paging message touser equipment according to a coverage level of the user equipment, sothat user equipment in different coverage areas can properly receive apaging message to some extent, and a quantity of times of re-sending apaging message is reduced, thereby avoiding an existing problem that theuser equipment fails to receive the paging message when a coverageintensity of a location in which the user equipment is located isextremely weak, where the problem is caused due to a fact that the basestation sends the paging message to the user equipment withoutconsidering the coverage intensity of the location in which the userequipment is located.

Embodiment 4

FIG. 7 shows a structural diagram of a base station 70, where the basestation 70 executes the paging method described in Embodiment 1. Asshown in FIG. 7, the base station 70 may include a receiving unit 701, acalculating unit 702, a determining unit 703, and a sending unit 704.

The receiving unit 701 is configured to receive a paging message of userequipment.

The paging message includes a user identity of the user equipment, andis used to wake up user equipment that is in an idle state.

The calculating unit 702 is configured to calculate a paging location ofthe user equipment according to the user identity received by thereceiving unit 701.

The paging location is used to send paging scheduling information, wherethe paging scheduling information is used to indicate a sending locationin which the base station sends an air interface paging message to theuser equipment. It should be noted that in this embodiment of thepresent invention, a frame format of a paging message scheduling cycleis different from that shown in FIG. 1. As shown in FIG. 4, in thisembodiment of the present invention, each paging cycle includes severalpaging super frames (Paging Super Frame), and each paging super frameincludes several paging occasions (Paging Occasion). The paging occasionis a radio frame and is equivalent to a paging frame shown in FIG. 1,and the paging occasion is a paging location and is used to beardownlink control information (Downlink Control Information, DCI), forexample, paging scheduling information. Each piece of downlink controlinformation occupies one radio frame and is equivalent to occupying onepaging occasion shown in FIG. 1.

The determining unit 703 is configured to determine a coverage level ofthe user equipment according to the user identity received by thereceiving unit 701.

The coverage level is used to indicate a network coverage intensity of alocation in which the user equipment is located, which may be dividedinto different levels according to a system regulation. Generally, threecoverage levels are designed in a narrowband system, and arerespectively: a level 0, a level 1, and a level 2. A higher coveragelevel indicates a lower network coverage intensity, and it is morenecessary to use a modulation and coding scheme that can increase thenetwork coverage intensity. The coverage level may be included in thepaging message, or pre-stored in the base station.

In addition, if the coverage level is not included in the pagingmessage, or is not pre-stored in the base station, the determining unit703 determines that the coverage level of the user equipment is a worstcoverage level.

The sending unit 704 is configured to send an air interface pagingmessage to the user equipment according to the coverage level of theuser equipment determined by the determining unit 703, and send, in thepaging location calculated by the calculating unit 702, pagingscheduling information, where the paging scheduling information is usedto indicate a location in which the air interface paging message issent, and the air interface paging message includes the paging messageof the user equipment.

The air interface paging message is one or more M2M paging messages thatare sent over a same air interface.

Further, the receiving unit 701 is specifically configured to:

receive, by using S1, a paging message of the user equipment sent by anMME; or receive, by using a Gb interface, a paging message of the userequipment sent by an SGSN.

Further, the calculating unit 702 is specifically configured to:

calculate the paging super frame according to a paging cycle of anetwork configuration, a paging super frame density, and an equipmentidentity of the user equipment;

for example, determine, according to a formula: SFN mod T=(T divN)*(UE_ID mod N), the paging super frame in which the paging location islocated; and

calculate the paging occasion according to a quantity of pagingoccasions within one paging super frame, the equipment identity of theuser equipment, and the paging super frame density; for example,determine, according to a formula: PO=floor(UE_ID/N) mod Ns, the pagingoccasion on which the paging location is located.

Symbols in the foregoing formulas: “mod” indicates dividing two integersto take a remainder; “div” indicates dividing two integers; “*”indicates multiplying two integers; “floor” indicates rounding down; and“/” indicates dividing two numbers.

Parameters in the foregoing formulas: UE_ID indicates the equipmentidentity of the user equipment that is used to identify the userequipment, and may be any one of the following identities: aninternational mobile user identity (English: International MobileSubscriber Identification Number, IMSI for short), a temporary mobileuser identity (English: Temporary Mobile User identity, TMSI for short),a globally unique temporary UE identity Globally Unique Temporary UEIdentity, and an international mobile equipment identity (English:International Mobile Equipment Identity, IMEI for short).

T indicates the paging cycle.

Ns indicates a quantity of paging occasions (PO) in one downlink controlinformation interval (DCI interval), and a value is: Ns=ceil (the lengthof a super frame/the length of DCI interval), that is, the quantity ofthe paging occasions is equal to an integer value that is obtained byrounding up a quotient of a length of the paging super frame divided bythe downlink control information interval. For example, in a current M2Mcommunications system, the length of the super frame is 64 radio frames(radio frame). In this case, if the DCI interval is 64 radio frames, Nsis 1 at most; if the DCI interval is 32 radio frames, Ns is 2 at most;or if the DCI interval is one radio frame, Ns is 64 at most.

N indicates the paging super frame density in a paging cycle. Forexample, N=T/4 indicates that in one paging cycle T, every four superframes may have only one paging super frame; N=T/2 indicates that in onepaging cycle T, every two super frames have only one paging super frame;and N=T indicates that in one paging cycle T, every super frame may be apaging super frame.

Further, the sending unit 704 is specifically configured to:

combine paging messages with a paging location and a coverage level thatare the same as those of the user equipment into a same paging recordlist;

make the paging record list included in an air interface paging messagethat is corresponding to the user equipment; and

use, according to a preset correspondence between a coverage level and amodulation and coding scheme MCS, an MCS that is corresponding to thecoverage level of the user equipment to perform modulation and coding onthe air interface paging message, and send the modulated and coded airinterface paging message to the user equipment.

The paging record list includes: a paging message and a correspondencebetween the paging message and the user equipment.

The correspondence between a coverage level and a modulation and codingscheme MCS is set in an M2M communication process according to arequirement, which is not limited in this embodiment of the presentinvention.

For example, if a paging super frame in a paging location of userequipment 1 is the first super frame, a paging occasion is the sixthradio frame, and a coverage level of the user equipment 1 is the level1, if a paging super frame in a paging location of user equipment 2 isthe first super frame, a paging occasion is the sixth radio frame, and acoverage level of the user equipment 2 is the level 1, and if a pagingsuper frame in a paging location of user equipment 3 is the first superframe, a paging occasion is the sixth radio frame, and a coverage levelof the user equipment 3 is the level 1, paging messages of the userequipment 1, the user equipment 2, and the user equipment 3 may becombined into a same paging record list, and the paging record list istransmitted by using an air interface.

Obviously, the base station may use a default modulation and codingscheme (for example, a modulation and coding scheme that iscorresponding to the worst coverage level) to send the paging message;may use, according to a coverage level of the user equipment sent by theMME or the SGSN, a corresponding modulation and coding scheme totransmit the paging message; or may use, according to a coverage levelof the user equipment stored in the inside of the base station, acorresponding modulation and coding scheme to transmit a paging messageset. Therefore, it is implemented that a paging message is sent to userequipment according to a coverage level of the user equipment, so thatuser equipment at different coverage levels determines, to some extent,a paging message that is corresponding to the user equipment, andreturns a response message indicating that the paging is successful tothe MME and the SGSN. However, because the user equipment may be movedto some extent, and a communication environment in which the userequipment is located is changing, a coverage level of the user equipmentdetermined by the base station this time cannot accurately represent acurrent coverage level of the user equipment; if a paging message issent after being modulated and coded according to an MCS that iscorresponding to the coverage level, the user equipment cannot obtainthe paging message because the user equipment fails to parse pagingscheduling information, which further brings about paging messagere-sending.

Therefore, to reduce a quantity of times of re-sending a paging messageof the user equipment, the determining unit 703 is further configured tore-determine a coverage level of the user equipment if the receivingunit 701 receives retransmission indication information that is used toinstruct to re-send a paging message of the user equipment.

The sending unit 704 is further configured to send an air interfacepaging message to the user equipment according to the coverage level ofthe user equipment re-determined by the determining unit 703.

Further, the determining unit 703 is specifically configured to:

if the retransmission indication message received by the receiving unit701 includes a current coverage level of the user equipment, determinethat the coverage level of the user equipment is the current coveragelevel; or

if the retransmission indication message received by the receiving unit701 does not include a current coverage level of the user equipment,lower the coverage level of the user equipment to a next inferiorcoverage level, or determine that the coverage level of the userequipment is the worst coverage level.

It may be learned from the foregoing that this embodiment of the presentinvention provides a base station. When receiving a paging message ofuser equipment, the base station calculates a paging location of theuser equipment and determines a coverage level of the user equipment;and the base station sends an air interface paging message to the userequipment according to the coverage level of the user equipment, andsends, in the paging location, paging scheduling information, where thepaging scheduling information is used to indicate a location in whichthe air interface paging message is sent, and the air interface pagingmessage includes the paging message of the user equipment. Therefore, itis implemented that in an M2M communications system, a base stationsends a paging message to user equipment according to a coverage levelof the user equipment, so that user equipment in different coverageareas can properly receive a paging message to some extent, and aquantity of times of re-sending a paging message is reduced, therebyavoiding an existing problem that the user equipment fails to receivethe paging message when a coverage intensity of a location in which theuser equipment is located is extremely weak, where the problem is causeddue to a fact that the base station sends the paging message to the userequipment without considering the coverage intensity of the location inwhich the user equipment is located.

Embodiment 5

FIG. 8 shows a structural diagram of user equipment 80, where the userequipment is configured to execute the paging method described inEmbodiment 2. As shown in FIG. 8, the user equipment 80 may include areceiving unit 801 and a parsing unit 802.

The receiving unit 801 is configured to receive, in a paging location,paging scheduling information sent by a base station.

The paging scheduling message is coded according to a modulation andcoding scheme MCS that is corresponding to a coverage level of the userequipment, and is used to indicate a location of an air interface pagingmessage sent by the base station to the user equipment, where thecoverage level of the user equipment is reported to an MME or an SGSN bythe user equipment, and delivered to the base station by the MME or theSGSN.

The air interface paging message includes a paging message record list,where the paging message record list includes a paging message of atleast one user equipment and a correspondence between the paging messageof the user equipment and the user equipment. In the paging messagelist, a paging location of a paging message and a coverage level thatare of each user equipment are the same as the paging location and thecoverage level that are of the user equipment.

It should be noted that a method for calculating a paging location bythe user equipment is the same as a method for calculating a paginglocation by the base station, and details are not described herein.

The parsing unit 802 is configured to decode, according to an MCS thatis corresponding to a current coverage level of the user equipment, thepaging scheduling information received by the receiving unit 801.

Further, if the parsing unit 802 successfully parses the pagingscheduling information, it indicates that a coverage level used when thebase station sends the paging scheduling information is the same as orlower than the current coverage level of the user equipment. As shown inFIG. 8A, the user equipment further includes:

an obtaining unit 803, configured to receive, according to the locationindicated by the paging scheduling information, the air interface pagingmessage sent by the base station, and obtain a paging message of theuser equipment from the air interface paging message.

Further, if the parsing unit 802 fails to parse the paging schedulinginformation, it indicates that a coverage level used when the basestation sends the paging scheduling information is higher than thecurrent coverage level of the user equipment. As shown in FIG. 8B, theuser equipment further includes:

a reporting unit 804, configured to report the current coverage level ofthe user equipment to the MME or the SGSN.

Further, the reporting unit 804 is specifically configured to:

report a random access message that carries the current coverage levelof the user equipment to the base station, and instruct the base stationto report the current coverage level of the user equipment to the MME orthe SGSN; or

report a registration Attach message, or a tracking area update TAUmessage, or a routing area update RAU message that carries the currentcoverage of the user equipment to the base station, and instruct thebase station to forward the Attach message, or the TAU message, or theRAU message to the MME or the SGSN.

It may be learned from the foregoing that this embodiment of the presentinvention provides user equipment. After the user equipment receivespaging scheduling information sent by a base station, if the userequipment successfully parses the paging scheduling information, theuser equipment receives, according to a location indicated by the pagingscheduling information, an air interface paging message sent by the basestation, and obtains a paging message of the user equipment from the airinterface paging message; or if the user equipment fails to parse thepaging scheduling information, the user equipment reports a currentcoverage level of the user equipment to the base station, so that whenre-sending a paging message to the user equipment, the base stationre-sends the message to the user equipment according to the currentcoverage level of the user equipment. Therefore, it is implemented thatin an M2M communications system, a base station sends a paging messageto user equipment according to a coverage level of the user equipment,so that user equipment in different coverage areas can properly receivea paging message to some extent, and a quantity of times of re-sending apaging message is reduced, thereby avoiding an existing problem that theuser equipment fails to receive the paging message when a coverageintensity of a location in which the user equipment is located isextremely weak, where the problem is caused due to a fact that the basestation sends the paging message to the user equipment withoutconsidering the coverage intensity of the location in which the userequipment is located.

Embodiment 6

FIG. 9 shows a structural diagram of a paging system, where the pagingsystem is used to execute the paging method described in Embodiment 3.As shown in FIG. 9, the paging system may include: a base station 91, atleast one user equipment 90, and a core network device 92.

A function of the base station 91 is the same as a function of the basestation 70 in the foregoing Embodiment 4, and a function of the userequipment 90 is the same as a function of the user equipment 80 in theforegoing Embodiment 5. Details are not described herein.

The core network device 92 may be an MME or an SGSN, and is configuredto send a paging message of an M2M91 to the base station 91, or sendretransmission indication information that is used to instruct tore-send a paging message of the user equipment.

It may be learned from the foregoing that this embodiment of the presentinvention provides a paging system. After receiving a paging message ofuser equipment sent by a core network device, a base station calculatesa paging location of the user equipment, sends an air interface pagingmessage to the user equipment according to a determined coverage levelof the user equipment, and sends, in the paging location, pagingscheduling information; after receiving the paging schedulinginformation sent by the base station, the user equipment parses thepaging scheduling message and obtains the paging message; if the parsingsucceeds, the user equipment returns a response message; or if theparsing fails, the user equipment reports a current coverage level ofthe user equipment, so that the base station re-sends a paging messageto the user equipment according to the current coverage level, or theuser equipment does not report a current coverage level, so that thebase station re-sends a paging message to the user equipment accordingto a re-determined coverage level. Therefore, it is implemented that inan M2M communications system, a base station sends a paging message touser equipment according to a coverage level of the user equipment, sothat user equipment in different coverage areas can properly receive apaging message to some extent, and a quantity of times of re-sending apaging message is reduced, thereby avoiding an existing problem that theuser equipment fails to receive the paging message when a coverageintensity of a location in which the user equipment is located isextremely weak, where the problem is caused due to a fact that the basestation sends the paging message to the user equipment withoutconsidering the coverage intensity of the location in which the userequipment is located.

Embodiment 7

FIG. 10 shows a structural diagram of a base station, where the basestation is configured to execute the paging method described inEmbodiment 1. As shown in FIG. 10, the base station 100 may include: acommunications unit 1001, a processor 1002, a memory 1003, and at leastone communications bus 1004, where the communications bus 1004 isconfigured to implement connection and mutual communication betweenthese devices.

The communications unit 1001 is configured to perform data transmissionwith an external network element.

The processor 1002 may be a central processing unit (English: centralprocessing unit, CPU for short).

The memory 1003 may be a volatile memory (English: volatile memory), forexample, a random access memory (English: random-access memory, RAM forshort); may be a non-volatile memory (English: non-volatile memory),such as a read-only memory (English: read-only memory, ROM for short), aflash memory (English: flash memory), a hard disk drive (English: harddisk drive, HDD for short), or a solid-state drive (English: solid-statedrive, SSD for short); or may be a combination of the foregoing types ofmemories, and provides an instruction and data to the processor 1002.

The communications unit 1001 is configured to receive a paging messageof user equipment.

The paging message includes a user identity of the user equipment, andis used to wake up user equipment that is in an idle state.

The processor 1002 is configured to calculate a paging location of theuser equipment according to the user identity received by thecommunications unit 1001.

The paging location is used to send paging scheduling information, wherethe paging scheduling information is used to indicate a sending locationin which the base station sends an air interface paging message to theuser equipment. It should be noted that in this embodiment of thepresent invention, a frame format of a paging message scheduling cycleis different from that shown in FIG. 1. As shown in FIG. 4, in thisembodiment of the present invention, each paging cycle includes severalpaging super frames (Paging Super Frame), and each paging super frameincludes several paging occasions (Paging Occasion). The paging occasionis a radio frame and is equivalent to a paging frame shown in FIG. 1,and the paging occasion is a paging location and is used to beardownlink control information (Downlink Control Information, DCI), forexample, paging scheduling information. Each piece of downlink controlinformation occupies one radio frame and is equivalent to occupying onepaging occasion shown in FIG. 1.

The processor 1002 is further configured to determine a coverage levelof the user equipment according to the user identity received by thecommunications unit 1001.

The coverage level is used to indicate a network coverage intensity of alocation in which the user equipment is located, which may be dividedinto different levels according to a system regulation. Generally, threecoverage levels are designed in a narrowband system, and arerespectively: a level 0, a level 1, and a level 2. A higher coveragelevel indicates a lower network coverage intensity, and it is morenecessary to use a modulation and coding scheme that can increase thenetwork coverage intensity. The coverage level may be included in thepaging message, or pre-stored in the base station.

In addition, if the coverage level is not included in the pagingmessage, or is not pre-stored in the base station, the processor 1002determines that the coverage level of the user equipment is a worstcoverage level.

The communications unit 1001 is further configured to send an airinterface paging message to the user equipment according to the coveragelevel of the user equipment determined by the processor 1002, and send,in the paging location calculated by the processor 1002, pagingscheduling information, where the paging scheduling information is usedto indicate a location in which the air interface paging message issent, and the air interface paging message includes the paging messageof the user equipment.

The air interface paging message is one or more M2M paging messages thatare sent over a same air interface.

Further, the communications unit 1001 is specifically configured to:

receive, by using S1, a paging message of the user equipment sent by anMME; or receive, by using a Gb interface, a paging message of the userequipment sent by an SGSN.

Further, the processor 1002 is specifically configured to:

calculate the paging super frame according to a paging cycle of anetwork configuration, a paging super frame density, and an equipmentidentity of the user equipment;

for example, determine, according to a formula: SFN mod T=(T divN)*(UE_ID mod N), the paging super frame in which the paging location islocated; and

calculate the paging occasion according to a quantity of pagingoccasions within one paging super frame, the equipment identity of theuser equipment, and the paging super frame density; for example,determine, according to a formula: PO=floor(UE_ID/N) mod Ns, the pagingoccasion on which the paging location is located.

Symbols in the foregoing formulas: “mod” indicates dividing two integersto take a remainder; “div” indicates dividing two integers; “*”indicates multiplying two integers; “floor” indicates rounding down; and“/” indicates dividing two numbers.

Parameters in the foregoing formulas: UE_ID indicates the equipmentidentity of the user equipment that is used to identify the userequipment, and may be any one of the following identities: aninternational mobile user identity (English: International MobileSubscriber Identification Number, IMSI for short), a temporary mobileuser identity (English: Temporary Mobile User identity, TMSI for short),a globally unique temporary UE identity Globally Unique Temporary UEIdentity, and an international mobile equipment identity (English:International Mobile Equipment Identity, IMEI for short).

T indicates the paging cycle.

Ns indicates a quantity of paging occasions (PO) in one downlink controlinformation interval (DCI interval), and a value is: Ns=ceil (the lengthof a super frame/the length of DCI interval), that is, the quantity ofthe paging occasions is equal to an integer value that is obtained byrounding up a quotient of a length of the paging super frame divided bythe downlink control information interval. For example, in a current M2Mcommunications system, the length of the super frame is 64 radio frames(radio frame). In this case, if the DCI interval is 64 radio frames, Nsis 1 at most; if the DCI interval is 32 radio frames, Ns is 2 at most;or if the DCI interval is one radio frame, Ns is 64 at most.

N indicates the paging super frame density in a paging cycle. Forexample, N=T/4 indicates that in one paging cycle T, every four superframes may have only one paging super frame; N=T/2 indicates that in onepaging cycle T, every two super frames have only one paging super frame;and N=T indicates that in one paging cycle T, every super frame may be apaging super frame.

Further, the communications unit 1001 is specifically configured to:

combine paging messages with a paging location and a coverage level thatare the same as those of the user equipment into a same paging recordlist;

make the paging record list included in an air interface paging messagethat is corresponding to the user equipment; and

use, according to a preset correspondence between a coverage level and amodulation and coding scheme MCS, an MCS that is corresponding to thecoverage level of the user equipment to perform modulation and coding onthe air interface paging message, and send the modulated and coded airinterface paging message to the user equipment.

The paging record list includes: a paging message and a correspondencebetween the paging message and the user equipment.

The correspondence between a coverage level and a modulation and codingscheme MCS is set in an M2M communication process according to arequirement, which is not limited in this embodiment of the presentinvention.

For example, if a paging super frame in a paging location of userequipment 1 is the first super frame, a paging occasion is the sixthradio frame, and a coverage level of the user equipment 1 is the level1, if a paging super frame in a paging location of user equipment 2 isthe first super frame, a paging occasion is the sixth radio frame, and acoverage level of the user equipment 2 is the level 1, and if a pagingsuper frame in a paging location of user equipment 3 is the first superframe, a paging occasion is the sixth radio frame, and a coverage levelof the user equipment 3 is the level 1, paging messages of the userequipment 1, the user equipment 2, and the user equipment 3 may becombined into a same paging record list, and the paging record list istransmitted by using an air interface.

Obviously, the base station may use a default modulation and codingscheme (for example, a modulation and coding scheme that iscorresponding to the worst coverage level) to send the paging message;may use, according to a coverage level of the user equipment sent by theMME or the SGSN, a corresponding modulation and coding scheme totransmit the paging message; or may use, according to a coverage levelof the user equipment stored in the inside of the base station, acorresponding modulation and coding scheme to transmit a paging messageset. Therefore, it is implemented that a paging message is sent to userequipment according to a coverage level of the user equipment, so thatuser equipment at different coverage levels determines, to some extent,a paging message that is corresponding to the user equipment, andreturns a response message indicating that the paging is successful tothe MME and the SGSN. However, because the user equipment may be movedto some extent, and a communication environment in which the userequipment is located is changing, a coverage level of the user equipmentdetermined by the base station this time cannot accurately represent acurrent coverage level of the user equipment; if a paging message issent after being modulated and coded according to an MCS that iscorresponding to the coverage level, the user equipment cannot obtainthe paging message because the user equipment fails to parse pagingscheduling information, which further brings about paging messagere-sending.

Therefore, to reduce a quantity of times of re-sending a paging messageof the user equipment, the processor 1002 is further configured tore-determine a coverage level of the user equipment if thecommunications unit 1001 receives retransmission indication informationthat is used to instruct to re-send a paging message of the userequipment.

The communications unit 1001 is further configured to send an airinterface paging message to the user equipment according to the coveragelevel of the user equipment re-determined by the processor 1002.

Further, the processor 1002 is specifically configured to:

if the retransmission indication message received by the communicationsunit 1001 includes a current coverage level of the user equipment,determine that the coverage level of the user equipment is the currentcoverage level; or

if the retransmission indication message received by the communicationsunit 1001 does not include a current coverage level of the userequipment, lower the coverage level of the user equipment to a nextinferior coverage level, or determine that the coverage level of theuser equipment is the worst coverage level.

It may be learned from the foregoing that this embodiment of the presentinvention provides a base station. When receiving a paging message ofuser equipment, the base station calculates a paging location of theuser equipment and determines a coverage level of the user equipment;and the base station sends an air interface paging message to the userequipment according to the coverage level of the user equipment, andsends, in the paging location, paging scheduling information, where thepaging scheduling information is used to indicate a location in whichthe air interface paging message is sent, and the air interface pagingmessage includes the paging message of the user equipment. Therefore, itis implemented that in an M2M communications system, a base stationsends a paging message to user equipment according to a coverage levelof the user equipment, so that user equipment in different coverageareas can properly receive a paging message to some extent, and aquantity of times of re-sending a paging message is reduced, therebyavoiding an existing problem that the user equipment fails to receivethe paging message when a coverage intensity of a location in which theuser equipment is located is extremely weak, where the problem is causeddue to a fact that the base station sends the paging message to the userequipment without considering the coverage intensity of the location inwhich the user equipment is located.

Embodiment 8

FIG. 11 shows a structural diagram of user equipment, where the userequipment is configured to execute the paging method described inEmbodiment 2. As shown in FIG. 11, the user equipment 110 may include: acommunications unit 1101, a processor 1102, a memory 1103, and at leastone communications bus 1104, where the communications bus 1104 isconfigured to implement connection and mutual communication betweenthese devices.

The communications unit 1101 is configured to perform data transmissionwith an external network element.

The processor 1102 may be a central processing unit (English: centralprocessing unit, CPU for short).

The memory 1103 may be a volatile memory (English: volatile memory), forexample, a random access memory (English: random-access memory, RAM forshort); may be a non-volatile memory (English: non-volatile memory),such as a read-only memory (English: read-only memory, ROM for short), aflash memory (English: flash memory), a hard disk drive (English: harddisk drive, HDD for short), or a solid-state drive (English: solid-statedrive, SSD for short); or may be a combination of the foregoing types ofmemories, and provides an instruction and data to the processor 1102.

The communications unit 1101 is configured to receive, in a paginglocation, paging scheduling information sent by a base station.

The paging scheduling message is coded according to a modulation andcoding scheme MCS that is corresponding to a coverage level of the userequipment, and is used to indicate a location of an air interface pagingmessage sent by the base station to the user equipment, where thecoverage level of the user equipment is reported to an MME or an SGSN bythe user equipment, and delivered to the base station by the MME or theSGSN.

The air interface paging message includes a paging message record list,where the paging message record list includes a paging message of atleast one user equipment and a correspondence between the paging messageof the user equipment and the user equipment. In the paging messagelist, a paging location of a paging message and a coverage level thatare of each user equipment are the same as the paging location and thecoverage level that are of the user equipment.

It should be noted that a method for calculating a paging location bythe user equipment is the same as a method for calculating a paginglocation by the base station, and details are not described herein.

The processor 1102 is configured to decode, according to an MCS that iscorresponding to a current coverage level of the user equipment, thepaging scheduling information received by the communications unit 1101.

Further, the processor 1102 is configured to: if the processor 1102successfully parses the paging scheduling information, which indicatesthat a coverage level used when the base station sends the pagingscheduling information is the same as or lower than the current coveragelevel of the user equipment, receive, according to the locationindicated by the paging scheduling information, the air interface pagingmessage sent by the base station, and determine a paging message of theuser equipment in the air interface paging message.

Further, the communications unit 1101 is configured to: if the userequipment fails to parse the paging scheduling information, whichindicates that a coverage level used when the base station sends thepaging scheduling information is higher than the current coverage levelof the user equipment, report the current coverage level of the userequipment to the MME or the SGSN.

Further, the communications unit 1101 is specifically configured to:

report a random access message that carries the current coverage levelof the user equipment to the base station, and instruct the base stationto report the current coverage level of the user equipment to the MME orthe SGSN; or

report a registration Attach message, or a tracking area update TAUmessage, or a routing area update RAU message that carries the currentcoverage of the user equipment to the base station, and instruct thebase station to forward the Attach message, or the TAU message, or theRAU message to the MME or the SGSN.

It may be learned from the foregoing that this embodiment of the presentinvention provides user equipment. After the user equipment receivespaging scheduling information sent by a base station, if the userequipment successfully parses the paging scheduling information, theuser equipment receives, according to a location indicated by the pagingscheduling information, an air interface paging message sent by the basestation, and obtains a paging message of the user equipment from the airinterface paging message; or if the user equipment fails to parse thepaging scheduling information, the user equipment reports a currentcoverage level of the user equipment to the base station, so that whenre-sending a paging message to the user equipment, the base stationre-sends the message to the user equipment according to the currentcoverage level of the user equipment. Therefore, it is implemented thatin an M2M communications system, a base station sends a paging messageto user equipment according to a coverage level of the user equipment,so that user equipment in different coverage areas can properly receivea paging message to some extent, and a quantity of times of re-sending apaging message is reduced, thereby avoiding an existing problem that theuser equipment fails to receive the paging message when a coverageintensity of a location in which the user equipment is located isextremely weak, where the problem is caused due to a fact that the basestation sends the paging message to the user equipment withoutconsidering the coverage intensity of the location in which the userequipment is located.

Embodiment 9

FIG. 12 shows a structural diagram of a paging system, where the pagingsystem is used to execute the paging method described in Embodiment 3.As shown in FIG. 12, the paging system may include:

a base station 121, at least one user equipment 120, and a core networkdevice 122.

A function of the base station 121 is the same as a function of the basestation 100 in the foregoing Embodiment 7, and a function of the userequipment 120 is the same as a function of the user equipment 110 in theforegoing Embodiment 8. Details are not described herein.

The core network device 122 may be an MME or an SGSN, and is configuredto send a paging message of an M2M121 to the base station 121, or sendretransmission indication information that is used to instruct tore-send a paging message of the user equipment.

It may be learned from the foregoing that this embodiment of the presentinvention provides a paging system. After receiving a paging message ofuser equipment sent by a core network device, a base station calculatesa paging location of the user equipment, sends an air interface pagingmessage to the user equipment according to a determined coverage levelof the user equipment, and sends, in the paging location, pagingscheduling information; after receiving the paging schedulinginformation sent by the base station, the user equipment parses thepaging scheduling message and obtains the paging message; if the parsingsucceeds, the user equipment returns a response message; or if theparsing fails, the user equipment reports a current coverage level ofthe user equipment, so that the base station re-sends a paging messageto the user equipment according to the current coverage level, or theuser equipment does not report a current coverage level, so that thebase station re-sends a paging message to the user equipment accordingto a re-determined coverage level. Therefore, it is implemented that inan M2M communications system, a base station sends a paging message touser equipment according to a coverage level of the user equipment, sothat user equipment in different coverage areas can properly receive apaging message to some extent, and a quantity of times of re-sending apaging message is reduced, thereby avoiding an existing problem that theuser equipment fails to receive the paging message when a coverageintensity of a location in which the user equipment is located isextremely weak, where the problem is caused due to a fact that the basestation sends the paging message to the user equipment withoutconsidering the coverage intensity of the location in which the userequipment is located.

The foregoing descriptions are merely specific implementation manners ofthe present invention, but are not intended to limit the protectionscope of the present invention. Any variation or replacement readilyfigured out by a person skilled in the art within the technical scopedisclosed in the present invention shall fall within the protectionscope of the present invention. Therefore, the protection scope of thepresent invention shall be subject to the protection scope of theclaims.

What is claimed is:
 1. A paging method, wherein the method comprises:receiving, by a base station, a paging message of user equipment,wherein the paging message comprises a user identity of the userequipment; calculating a paging location of the user equipment accordingto the user identity of the user equipment, and determining a coveragelevel of the user equipment; and sending an air interface paging messageto the user equipment according to the coverage level of the userequipment, and sending, in the paging location, paging schedulinginformation, wherein the paging scheduling information is used toindicate a location in which the air interface paging message is sent,and the air interface paging message comprises the paging message of theuser equipment.
 2. The paging method according to claim 1, wherein thedetermining a coverage level of the user equipment comprises: if thepaging message does not carry the coverage level of the user equipment,and the base station does not store a correspondence between the userequipment and the coverage level, determining that the coverage level ofthe user equipment is a worst coverage level.
 3. The paging methodaccording to claim 1, wherein the sending an air interface pagingmessage to the user equipment according to the coverage level of theuser equipment comprises: combining paging messages with a paginglocation and a coverage level that are the same as those of the userequipment into a same paging record list; making the paging record listcomprised in an air interface paging message that is corresponding tothe user equipment; and using, according to a preset correspondencebetween a coverage level and a modulation and coding scheme (MCS), anMCS that is corresponding to the coverage level of the user equipment toperform modulation and coding on the air interface paging message, andsending the modulated and coded air interface paging message to the userequipment.
 4. The paging method according to claim 1, wherein thereceiving, by a base station, a paging message of user equipmentcomprises: receiving, by the base station, a paging message of the userequipment sent by a mobility management entity (MME) or a servinggeneral packet radio service support node (SGSN).
 5. The paging methodaccording to claim 4, wherein the calculating a paging location of theuser equipment comprises: calculating, according to a paging cycle of anetwork configuration, a paging super frame density, and an equipmentidentity of the user equipment, a paging super frame in which the paginglocation is located; and calculating, according to a quantity of pagingoccasions within one paging super frame, the equipment identity of theuser equipment, and the paging super frame density, a paging occasion onwhich the paging location is located, wherein the quantity of the pagingoccasions within the paging super frame is determined according to alength of the paging super frame and a downlink control informationinterval.
 6. The paging method according to claim 1, wherein the methodfurther comprises: re-determining a coverage level of the user equipmentif the base station receives retransmission indication information thatis used to instruct to re-send a paging message of the user equipment;and sending an air interface paging message to the user equipmentaccording to the re-determined coverage level of the user equipment. 7.The paging method according to claim 6, wherein the re-determining acoverage level of the user equipment comprises: if the retransmissionindication message received by the base station comprises a currentcoverage level of the user equipment, determining that the coveragelevel of the user equipment is the current coverage level; or if theretransmission indication message received by the base station does notcomprise a current coverage level of the user equipment, lowering thecoverage level of the user equipment to a next inferior coverage level,or determining that the coverage level of the user equipment is theworst coverage level.
 8. A base station, comprising: a transceiver,configured to receive a paging message of machine-to-machine userequipment, wherein the paging message comprises a user identity of theuser equipment; and a processor, configured to calculate a paginglocation of the user equipment according to the user identity receivedby the transceiver, and determine a coverage level of the userequipment, wherein the transceiver is further configured to send an airinterface paging message to the user equipment according to the coveragelevel of the user equipment determined by the processor, and send, inthe paging location calculated by the processor, paging schedulinginformation, wherein the paging scheduling information is used toindicate a location in which the air interface paging message is sent,and the air interface paging message comprises the paging message of theuser equipment.
 9. The base station according to claim 8, wherein theprocessor is configured to: if the paging message does not carry thecoverage level of the user equipment, and the base station does notstore a correspondence between the user equipment and the coveragelevel, determine that the coverage level of the user equipment is aworst coverage level.
 10. The base station according to claim 8, whereinthe transceiver is configured to: combine paging messages with a paginglocation and a coverage level that are the same as those of the userequipment into a same paging record list; make the paging record listcomprised in an air interface paging message that is corresponding tothe user equipment; and use, according to a preset correspondencebetween a coverage level and a modulation and coding scheme (MCS), anMCS that is corresponding to the coverage level of the user equipment toperform modulation and coding on the air interface paging message, andsend the modulated and coded air interface paging message to the userequipment.
 11. The base station according to claim 8, wherein thetransceiver is configured to: receive a paging message of the userequipment sent by an MME or an SGSN.
 12. The base station according toclaim 8, wherein the processor is configured to: calculate, according toa paging cycle of a network configuration, a paging super frame density,and an equipment identity of the user equipment, a paging super frame inwhich the paging location is located; and calculate, according to aquantity of paging occasions within one paging super frame, theequipment identity of the user equipment, and the paging super framedensity, a paging occasion on which the paging location is located,wherein the quantity of the paging occasions within the paging superframe is determined according to a length of the paging super frame anda downlink control information interval.
 13. The base station accordingto claim 8, wherein the processor is further configured to re-determinea coverage level of the user equipment if the transceiver receivesretransmission indication information that is used to instruct tore-send a paging message of the user equipment; and the transceiver isfurther configured to send an air interface paging message to the userequipment according to the coverage level of the user equipmentre-determined by the processor.
 14. The base station according to claim13, wherein the processor is configured to: if the retransmissionindication message received by the base station comprises a currentcoverage level of the user equipment, determine that the coverage levelof the user equipment is the current coverage level; or if theretransmission indication message received by the base station does notcomprise a current coverage level of the user equipment, lower thecoverage level of the user equipment to a next inferior coverage level,or determine that the coverage level of the user equipment is the worstcoverage level.
 15. User equipment, comprising: a transceiver,configured to receive, in a paging location, paging schedulinginformation sent by a base station, wherein the paging schedulinginformation is coded according to a modulation and coding scheme (MCS)that is corresponding to a coverage level of the user equipment, and isused to indicate a location of an air interface paging message sent bythe base station to the user equipment, wherein the coverage level ofthe user equipment is reported to an MME or an SGSN by the userequipment, and delivered to the base station by the MME or the SGSN; anda processor, configured to decode, according to an MCS that iscorresponding to a current coverage level of the user equipment, thepaging scheduling information received by the communications unit. 16.The user equipment according to claim 15, wherein if the processorsuccessfully parses the paging scheduling information, the transceiveris configured to receive, according to the location indicated by thepaging scheduling information, the air interface paging message sent bythe base station, and the processor is further configured to: obtain apaging message of the user equipment from the air interface pagingmessage; and the transceiver is further configured to: if the processorfails to parse the paging scheduling information, report the currentcoverage level of the user equipment to the base station.
 17. The userequipment according to claim 15, wherein the transceiver is configuredto: report a random access message that carries the current coveragelevel of the user equipment to the base station, and instruct the basestation to report the current coverage level of the user equipment tothe MME or the SGSN; or report a registration Attach message, or atracking area update TAU message, or a routing area update RAU messagethat carries the current coverage of the user equipment to the basestation, and instruct the base station to forward the Attach message, orthe TAU message, or the RAU message to the MME or the SGSN.